[Yaskawa SigmaII] Faulty/dead speed reference input ?

Hello,

I was wondering if a faulty or dead speed reference input in a Yaskawa SigmaII SGDH-02 servopack was possible ? I am supplying 5V to it and SigmaWin won't mention "Speed Reference Input" nor a value. I tried to reset, redo or exchange anything I thought of and my conclusion is :

• servopack and motor jog fine using Sigmawin,
• power, encoder, data cables are fine,
• encoder outputs (same cable) from the servopack are fine.

Is there any chance it would be a replaceable 2-cents piece inside the servopack ? or did I miss the obvious "ignore speed reference input" parameter ? I certainly hope so.

Thank you very much,
Julien

Julien said:

Hello,

I was wondering if a faulty or dead speed reference input in a Yaskawa SigmaII SGDH-02 servopack was possible ? I am supplying 5V to it and SigmaWin won't mention "Speed Reference Input" nor a value. I tried to reset, redo or exchange anything I thought of and my conclusion is :

• servopack and motor jog fine using Sigmawin,
• power, encoder, data cables are fine,
• encoder outputs (same cable) from the servopack are fine.

Is there any chance it would be a replaceable 2-cents piece inside the servopack ? or did I miss the obvious "ignore speed reference input" parameter ? I certainly hope so.

Thank you very much,
Julien

Click to expand...

Welcome to the Forum!

I am not familiar with the Yaskawa Servos, I have only worked on their VFDs. However, I doubt that there is 2 Cent Component that will solve your problem.

Is this a new, or an existing installation?

Is the Speed Reference Unipolar or Bipolar? i.e. 0-10VDC or +/- 10VDC.

Stu.....

Hello,

and thank you for your answer.

Yaskawa SigmaII speed reference is +/-10V (one input and ground). The same connector is used for the speed reference, servo enable, limits, encoder outputs. I'm guessing the common ground isn't dead as the other inputs/outputs are fine.

This is a used servopack bought on eBay. I bought it ages ago but only tested it using "manual jog" mode before.

I own a few other Yaskawa (mainly 400W, no other 200W) who do work fine.

I forgot to mention all cables are shielded.

Thank you,
Julien

Julien said:

Hello,

and thank you for your answer.

Yaskawa SigmaII speed reference is +/-10V (one input and ground). The same connector is used for the speed reference, servo enable, limits, encoder outputs. I'm guessing the common ground isn't dead as the other inputs/outputs are fine.

This is a used servopack bought on eBay. I bought it ages ago but only tested it using "manual jog" mode before.

I own a few other Yaskawa (mainly 400W, no other 200W) who do work fine.

I forgot to mention all cables are shielded.

Thank you,
Julien

Click to expand...

Julien:

I downloaded the Manual from Yaskawa, so hopefully it is the same one you are using.

I would go through all the Parameters in Section 9.7 of the Manual. Look for something weird in one of them. I see some that could shut you down if they are incorrect. For example, the Speed Reference Offset, and the Zero Clamp Parameter.

Stu....

You have to start with parameter Pn000. Make sure your control method is "Speed Control(Analog Reference)"

Hello,

Have a nice day,
Julien

Julien said:

Hello,

the drive was reset to "Speed control" multiple times.
​

Applying 5V to V-REF/SG, I could verify that it was entering the drive (to exclude cable/connector/noise issues) but SigmaWin wasn't reporting anything. I feared the "speed reference" circuit inside the drive was dead. So I switched to "torque control", used T-REF/SG and everything worked like a charm.
​

I would love to tell the drive "use Speed control but using T-REF input pin".
​

Have a nice day,
Julien

Click to expand...

It seems unlikely that the Servo Drive would support that, or they wouldn't bother with separate Inputs. It is certainly possible there is a failure in the Speed Input Components if you can't find a Parameter Settings issue. Have you had a look for anything obvious? Like burnt Components, or bad Solder Joints etc?

Stu....

Yes I did open it but didn't found anything obvious and couldn't track the circuit thru the PCB.

Thank you for the help, I guess it will be torque mode from now on.